Flotation machine



Jan. 9, 1934. A. c. DAMAN 1,942,803

FLOTAI ION MACHINE Filed MaICh 9, 1928 E57-, gf 5*. BY

A TTORNE Y.

Patented Jan. 9, 1934 l -UNITED STATES PATENT oFFicE FLOTATION MACHINE y Arthur C. Daman, Denver, Colo.

Application March 9, 1928. Serial No. 260,335 s claims. (ci. 20e-169) Machines of this type have heretofore been' limited to very fine mesh material owing to the fact that it was impossible for theimpeller to lift coarse material. The present invention is designed so that the ore is fed directly upon the impeller by gravity, and no suctionoi` lifting action is required. This enables the machine to handle relatively coarse material of a mesh heretofore considered impossible for flotation purposes Another object of the invention is to eliminate the usual inter-cell partitions so that the material can readily travel fromr lone impeller to the next without being required to be raised and forced over an inter-cell partition. This also facilitates the action of the machine upon coarse material. i

Other objects and advantages reside in the detail construction of the invention, which is designed for simplicity, economy, and efficiency. These will become more apparent from the following description.

In the following detailed description of the invention reference is had to the accompanying drawing which forms a part hereof. Like numerals refer to like parts in all views of the drawing and throughout the description.

In the drawing: 4

Fig. 1 is a plan view of one embodiment of the invention.

Fig. 2 is a vertical longitudinal section therethrough taken on the line 2--2, Fig. 1.

Figs. 3 and 4 illustrate a vertical section and a plan view, respectively, of a second embodiment of the invention.

Figs. 5 and 6 illustrate a vertical section and a plan view, respectively, of a third embodiment of the invention.

Fig. '7 is a cross section through the form of Fig. 1 taken on the line 7 7, Fig. 1.

The machine comprises any desired -number ofsimilar units placed adjacent to each other within a relatively long, common, flotation tank. 10.

Each of the units comprises a liner or bowl 11, preferably of relatively heavy cast iron. The bowl 11 is preferably rectangular in shape with 60 rounded corners at the intersections between its sides and between its sides and bottom, as illustrated. Above the bottom of the -bowl 11, and parallel therewith, a deectingdisc or impeller shield `V12 is placed through which a vertical, central cyl- 65 inder 13 communicates. The shield 12 and cylinder 13 Iare supported upon a spider 14 upon the bowl 11 and from the tank 10, so that the cylinder 13 opens above the solution line'in the tank. 70 A vertical shaft 15 extends concentrically through the cylinder 13 and terminates between5 .the shield 12 and the bottom of the bowl 11 in an impeller 16. The impeller 16 is preferably of the shrouded type, that is, it comprises a circular disc, from the upper surface of which project impeller vanes. If desired, impeller vanes may also be placed on the lower surface of the disc as illustrated at 27. The shaft 15 is supported in any desired manner, its method of support forming no part of the present invention.

In use the material to be floated is fed through a feed inlet pipe 17 which opens through the shield 12 of the first unit. This material falls directly upon the impeller 16, so that, regardless of the size or weight of the particles, they are directly acted upon by the impeller and are thrown outwardly by the rotation thereof against the sides of the bowl 11. The curvature of the bowl sides directs the material upwardly around the cylin-v der 13. Air is drawn into the whirling mass of material by the action of the impeller through the cylinder 13 and is beaten into small bubbles in intimate contact with the ore particles.

A portion of the upwardly thrown material will be engaged by the air bubbles and carriedoi in the froth as is usual in machines of this character. Another portion will fall back upon the shield 12 and be drawn through openings 18, 100 formed therein, directly upon the impeller which will again project it upwardly in the solution in contact with the air bubbles. Still another portion of the material will be carried over to the next unit and will fall upon the. shield 12 of that unit 105 where it will pass through the openings 18 therein and be projected upwardly by the `second impeller. Thus in each unit, fresh material from the preceding unit is being treated. previously treated matter from the same unit is being re- 11g material more rapidly through the series of units,

the forms of the invention shown in Figs. 3 to 6 may be employed. In Figs. 3 and 4, a feed pipe 20 projects from each of the cylinders 13 so as to be in the path of the falling material of the preceding unit. Thus, a portion of the falling material from each unit will be constantly drawn into the feed pipe of the subsequent unit. If desired, deflectors 21 may be placed immediately ahead of the feed pipes so as to deect the falling matel rial toward the feed pipe and away from the peller.

action of the previous impeller.

Another method for passing the heavy material more rapidly through the units is shown in Figs. 5 and 6, in which, troughs 22 are employed to deect the falling material of the preceding cell onto the shield 12 of the succeeding cell so that it will iiow through the openings 18 to the im- The floated mineral is gathered in a froth launder 23 which extends throughout the length of the tank l0. At each unit a froth return pipe 24, controlled by a valve 25, is provided between the froth launder 23 and the cylinder 13 of that unit. By this arrangement, at any desired stage of treatment the floated material can be returned to any desired unit for retreatment such as to an earlier stage of treatment.

1t is desired to call attention to the basic principle of this invention, that is, the placing or dropping of the material directly upon the impeller and not-requiring the impeller to lift the material into it by suction. t has been found that by the use of this principle, material of onequarter inch mesh or larger can be treated, whereas, before this invention the pulp had to be ground to mesh or nner before it could be admitted to the flotation machine.

With the present invention ore may be fed directly from the crusher to the flotation machine without the use of classiers or the like. The otation' machine will then oat all material which has reached the necessary neness or from which the mineral has been freed and will pass the remaining material through the machine regardless of its coarseness, thus acting as a classifier to return the coarser material for regrinding.

suspended matter in the solution will settle on the shields 12 and will not clog the impellers or interfere with again starting the machine.

While the machine is in operation the incorning material from the feed in return pipe 17 will create a constant lengthwise current in the solution which will carry the pulp across the upwardly flowing streams of bubbles, thus giving each particle of pulp an infinite number of air contacts before it leaves the machine.

If desired, the shield 12 can be formed as a part of the impeller so as to rotate therewith.

While a specific form of the improvement has been described and illustrated herein, it is desired to be understood that the same may be varied, within the scope of the appended claims, without departing from the spirit of the invention.

Having thus described the invention, what I claim and desire secured by Letters Patent isz- 1. Flotation apparatus comprising a tank, a series of bowls in the bottom of the tank adjoining one another for the direct passage of material from one to another in an unobstructed progressive movement, impellers in the bowls to effect said movement, the bowls separately concentrating material to the direct influence of the respective impellers, and leaving an uninterrupted quiescent zone common to all bowls immediately above the same, and a perforated plate above each impeller disposed to intercept material passing to the respective bowl and spaced from the circumferential wall of the bowl to pro* vide an unrestricted annular passage for material moving upwardly under influence of the im- 1".'

peller and restricting the inuence of the agitationimmediately above the impeller to permit the free settling of solids onto said plate from the quiescent zone above same.

2. Flotation apparatus comprising a tank, a series of open compartments in the bottom of the tank adjoining one another for the direct passage of material from one to another in an unobstructed movement, aerating impellers in the compartments adapted to move material progressively from one compartment to another in said series by upward thrust and downwardly directed suction, the tank having an uninterrupted quiescent zone common to all compartments immediately above the same, and means in the quiescent zone to entrap solids in suspension and effect their return to the influence of the impellers. i

3. Flotation apparatus comprising a tank, a series of open compartments in the bottom of the tank adjoining one another for the direct passage of material from one to another in an unobstructed movement, aerating impellers in the compartments adapted to move material progressively from one compartment to another in said series by upward thrust and downwardly directed suction, the tank having an uninterrupted quiescent Zone common to all compartments immediately above the same, and means -on the compartments to conduct material from next succeeding compartment.

ARTHUR C. DAMAN.

Eli 

